Method of maintaining a constant volume in the air chamber of liquidquantity-indicating devices



June 12, I928,

J. MACCALLUM,

M aw? 2 We? MO I 4 V,

mm m

' METHOD OF MAINTAINING A CONSTANT VOLUME IN THE AIR CHAMBER PatentedJune 12, 1928.

UNITED 1 STATES PATENT OFFICE.

JAMES MACCALLUM, JR, OF UNIVERSITY CITY, MISSOURI.

METHOD OF MAINTAINING A CONSTANT VOLUME IN THE AIR CHAMBER OF LIQUID-QUANTITY-INDICATING DEVICES.

Original application filed June 5, 1920, serial No. 386,674. Divided andthis application iiled November 8, 1926. Serial No. 146,615.

My invention relates to improvements in the method of maintaining aconstant volume in the air chamber of a liquid quantity indicatingdevice and has for its primary object the method of automaticallymaintainin the volume in the pressure chamber of an indicating deviceconstant by supplying additional air to said chamber by the movement ofthe liquid in a container.

A further object is to supply air or other gaseous pressure carryingmedium to the pressure chamber of a quantity indicating device duringthe filling of the container.

A still further object is to aerate the liquid while being poured intothe con.-

tainer and to discharge a portion of this aerated liquid beneath thepressure chamber of a quantity indicating device where the air willrelease itself from the liquid and ass beneath and into the pressurecham er and thereby restore any loss of volume in the chamber.

One serious objection to quantity indicators of the pressure type isthat a diminution of the pressure carrying medium used to operate theindicator caused either by the contraction or com ression of the gaseousmedium in the con uit and pressure chamber or by 'the absorption of saidgaseous medium by the liquid or by temperature changes or otherhydrostatic phenomena, which cause a change in volume, permits liquidto; enter the pressure chamber result ing in an incorrect reading of theindicator or gauge. Prior inventors have sought to overcome thisobjection by providlng a pump or compressor by means of which air underpressure can be admitted to the pressure chamber or conduit at intervalsto compensate for the absorption or loss of volume in the chamber andthus re-establish correct pressure. Others have attempted to overcomethis objection by providing a tube to which the operator places hismouth and by blowing restores this loss in volume, but by these variousmethods considerable attention was required-on'the part of the user tomaintain them in operative condition and, if not attended to at properintervals, the indication would be incorrect but by my method no suchattention is required.

This application is a division of my application filed June 5th, 1920,Serial No. 386,674 for quantity-indicators for liquids.

In the drawings:

Fig. 1 is a vertical sectional view of a quantity indicator for liquidsby which my method can be carried out; and

Fig. 2 is an enlarged vertical sectional view of the pressure chamberand certain of the parts that are associated with the same.

In the construction of my device 3 represents a liquid container, ortank. This tank is provided with a bottom 4, in which an opening 5 isformed. Around this opening issecured a ring 6, which has a portion 7proj ecting upwardly into the tank, thus forming a. sediment trap. Thisupward projection is provided with a right-angular downward projection8, the outer face or vertical portion of which is provided with screwthreads 9, over which a clamping ring 10 is adapted to be secured.Projecting within the container, or tank 3 is a cup 11, that surroundsthe lower portion of a pressure chamber 14, said cup being provided witha plurality of outwardly bent portions or flutes 12. These flutes formpassages 13 between the cup 11 and the air pressure chamber 14. The airpressure chamber 14 and the cup 11 are secured together at the portionsof the cup located between the flues. The air pressure chamber 14 isprovided with a. concave bottom 15, the center of which is rovided witha depressed portion 16. The epressed portion has the openings 17 formedtherein, as well as acentral openin 18 through which the portion 19 ofthe draining plug 20 passes. The cup 11 is rovided with a horizontallyprojecting portion 21 that forms a flange 22. After the flange 22 hasbeen formed, the material out of which the cup is constructed againextends horizontally toward the center, thus forming a horizontalportion 23, and between the horizontal portions 21 and 23 is securelyclamped the flange 24 of the defleeting shield 25. This deflectingshield is made convex and has a central opening 26* through which theportion 19 of the drain plug passes. The cup 11, as well as thedefleeting shield 25, are provided with openings 26; these openingsregistering and allowing communication between the tank and theunderside of the shield 25. Through one of these openings is insertedthe end 26" of the filling spout 27. This spout is provided near itsupper end with the perforatedienlargement 28, the perforations allowingthe escape of liquid into the tank in the event the liquid is poured infaster than the .end 26 will permit to escape. These perforationspermit, as is obvious, the ingress of air into the tube 27 and a certainvolume of air will be contained in said tube above the liquid within thetube. The air above the liquid within the tube will be displaced andcarried down through the tube and discharged with the liquid by theweight and movement or pres sure of the liquid which is splashed throughthe openings when the liquid in the container is agitated. Secured tothe upper end of the enlargement 28 is the cup 29, which has air vents30 formed therein. Within the container is located the air pipe31, whichhas its end 32 secured to the top of the compressed air chamber 14, itsend 33 being secured within the coupling 34. This coupling is securedthrough the side of the container 3 by means of the lock nut 36 and tothis coupling is secured the pipe 35, which has its opposite end securedto the gauge 37. The filler pipe 27 is provided with a flange 38 so thatit can be attached to the container by means of screws 39. Within thefiller pipe is secured a rod 40, which projects entirely across theopening and is for the purpose of splitting the flow of liquid whilebeing poured into the container and thus allowing it to grasp and hold acertain amount of air in the form of bubbles, which are delivered by theliquid underneath the shield 25.

The operation of my device is, as follows:

The container being empty, there is only atmospheric pressure within thepressure chamber 14; when the filling of the container is commenced theliquid will pass down through the filling tube 27, be split by the rod40 and become aerated i. e., carry air in the shape of bubbles with it,and out through the opening 26, which air will be released from theliquid and strike the under portion of the shield 25. The liquid willcontinue to pass and rise until a liquid seal has been formed, whichwill be when the liquid contacts withthe bottom edge of the air pressurechamber. After this seal has been formed the'bubbles will rise throughthe liquid and lodge against -the bottom 15, and after a suflicientamount of air has accumulated underneath the bottom to uncover theopenings 17, the air will be permitted to enter these openings and riseupward in the air pressure chamber '14 and also fill the space beneaththe bottom 15 to the lower edge of the pressure chamber. As the liquidcontinues to flow through the pipe 27, it will flow through thepassageways 13 formed by the flutes 12 and openings 26 and thereby sealthe air against escape, and also exerts an upward pressure on the air inthe chamber. The air pressure set up within the chamber is sutficient toprevent the entrance of liquid. As the height of liquid in the tankincreases, the pressure in the chamber increases proportionately. The betransferred to the gauge 37 y means of the pipes 31 and 35, and thusindicate the quantity of liquid within the container.

It is a well known fact that liquids, especially when confined andcaused to exert pressure on air, or other gaseous medium, will absorb acertain amount thereof, and in or der to make my device accuratelyoperative an additional supply of air or gaseous medium to take theplace of that absorbed must be furnished or the device would becomeinaccurate. This additional medium is supplied by the replenishing ofthe liquid in the tank through the spout 27 and a so by the splashing ofthe liquid in the tank into the openings or perforations of the spoutwhen the liquid is agitated. When it is desired to drain the entiretank, or in the event that the openings become clogged the sediment plu20 may be removed and the entire tank was red out without disturbing anyof the pipe connections or the filter tube.

One purpose of forming the openings 1n the enlarged portion 22 is thatwhen liquid is forced into the tank from a measuring pump the opening 26at the bottom of the filler tube will not be sufficient to allow all ofthe liquid to pass therethrough but the tube 27 will become filled andhave a sort of checking effect on the liquid contained therein; whenthis occurs the openings will allow the excess liquid to passtherethrough and into the container.

It is obvious that the perforations formed in the enlargement 28 willpermit the ingress of air into the tube 27 and this free air, asdistinguished from the air in the liquid, will be discharged downwardlythrough the tube and escape with the liquid contained in the tube,beneath the air pressure chamber. My invention contemplates two methodsof replacing the absorbed air in the air pressure chamber. One is bymeans of the liquid poured through the tube and the other by means ofthe air admitted either as trapped air or as air contained in the liquidwhich passes through the perforations by the splashing of the liquid inthe tank when the said liquid is agitated. It is obvious that in themovement of the vehicle on which the a )paratus is used a certainquantity of liqui will pass through the perforations and will enter thetube and be discharged beneath the pressure chamber. This splashedliquid contains air which will escape in the form of air bubbles intothe ressure chamber, and, as previously pointe out, a certain quantityof air will also pass into the tube 27, and form above the liquid levelin the tube, and when the volume of splashed prcssu re will liquidthrough the openings is greater than the volume of the liquid below theair, this air will be trapped and also be discharged beneath the airpressure chamber.

In order to carry out my method by a device of this character it isobvious that in order for the gauge to operate accurately that aconstant volume of gaseous pressure medium must be maintained in thechamber 14, and broadly speaking the object of my invention is tomaintain this volume constant automatically regardless of any causewhich contributes to fluctuations or variations of this volume.

It is also obvious that the method described herein is not limited inits applications to use in connection with tanks or containers forgasoline or other volatile hydrocarbons nor only where air is thegaseous pressure medium used in the pressure chamer but it is apparentthat my method may be used in connection with other liquids and othergaseous media in the pressure cham' ber can be employed than thosespecified without departing from the spirit of my in.-

vention.

Having fully described my invention, what I claim is 1. The method ofsupplying air to the pressure chamber and line of a quantity indicatorfor liquids within a container which consists in confining againstdiffusion the air to be supplied, imparting movement to the liquid to bemeasured by moving the container, and utilizing the movement and weightof said liquid to deliver said confined air to the pressure chamber.

2. The herein described method of supplying air to maintain a normalliquid level in the air pressure chamber of a quantity indicating devicefor liquids which consists in agitating a liquid containing trapped airdelivering said liquid and air beneath sai chamber, and then permittingsaid air to rise and pass into said air pressure chamber.

3. The method of supplying air to the pressure chamber in a quantityindicating device for liquids, which method consists in agitating theliquid so as to separate an independent volume of liquid from the mainbody thereof, and utilizing the volume of liquid while being se' aratedto trap air and the weight of sai separated liquid to force'said trappedair beneath and into the pressure chamber.

4. The method of introducing air into the pressure chamber of a quantityindicator for liquids, which is located below the surface of the liquidand in communication therethe same beneath the surface of the liquid andinto the pressure chamber.

5. The method of automatically delivering air to the pressure chamber ofa quantity indicating device for liquids within a container, whichpressure chamber is submerged in and communicates at its bottom withsaid liquid, which method consists in impartin movement to the liquid tobe measured and thereby elevating portion thereof in such manner as toentrap air therein, confining said entrapped air and the portionof theliquid which has entrapped it against lateral diflusion, the weight ofsaid liquid above the entrapped air causing said air to be forceddownwardly so as to deliver the same beneath said pressure chamber tomaintain the volume therein.

In testimony whereof I have aflixed my signature.

JAMES MACCALLUM, J R.

